Apparatus for automatically centering a moving elongated object



E. T. LORIG Dec. 20, 1955 APPARATUS FOR AUTOMATICALLY CEINTERING A MOVING ELONGATED OBJECT 2 Sheets-Sheet 1 Filed July 28, 1952 Full.

1020691507: [DW/N 771006,

Dec. 20, 1955 E. T. LORIG 2,727,400

APPARATUS FOR AUTOMATICALLY CENTERING A MOVING ELONGATED OBJECT Filed July 28, 1952 2 Sheets-Sheet 2 1120612601: ////Y////% am/v flo /6,

g 2,727,400 Patented? Dec. 20, 19155 APPARATUS FOR AUTOMATICALLY CENTERING A MOVING ELONGATED OBJECT Edwin T. Lorig, Pittsburgh, Pa., assignor to United States Steel Corporation, a corporation of New Jersey Application July 28, 1952, Serial No. 301,321

6 Claims. (Cl; 74--241) This invention relates to apparatus for automatically centering a moving object, particularly a strip or strip like material. Apparatus suitable for this purpose is dis. closed in my prior Patents Nos. 2,593,157 and 2,593,158. However, for very diflicult tracking problems such as the tracking of grinding belts traveling at high speeds under variable laterally applied grinding loads the rolls disclosed in my above mentioned patentsare not entirely satisfactory.

It is therefore an object of my invention to provide automatic self-centering rolls particularly suitable for extremely difi'icult tracking problems.

This and other objectswill be more apparent after referring to the following specification and attached drawings in which:

Figure l is a top plan view of apparatus embodying my invention;

Figure 2 is a sectional view of one specific type of roll embodying my invention;

Figure 3 is a fragmentary view showing a modification of Figure 2;

Figure 4 is a view, similar to Figure 2, showing a second embodiment of my invention;

Figure 5 is a schematic view showing one adaptation of my invention;

Figure 6 is a schematic view showing another adaptation of my invention; and

Figure 7 is a fragmentary view showing a modification of Figure 4.

Referring more particularly to the drawings, reference numeral 2 indicates a pair of spaced apart rotatable rolls or pulleys supporting an endless belt B. The rolls 2 are self-centering rolls of the general type shown in my above mentioned Patent No. 2,593,157. Each of the pulleys 2 consists of a pair of opposed rotatable rolls 4 which are mounted on a stationary bent shaft 6. The axis of the shaft is also bent so that the rolls 4 will rotate about the axes 8, 10 and 10, 12. As best shown in Figures 1 and 2, the axes 8, 10 and 10, 12 intersect at the point 10 between the rolls 4 and diverge away from the direction of approach of the belt B. Each of the rolls 4 has a rim portion 14 which is connected to a hub portion 16 by means of webs 18 and 20. A set collar 22 is fastened on the shaft 6 at each end thereof and bears against the adjacent hub 16. The shaft 6 is supported in bearings 24. The adjacent ends of the rims 14 are provided with openings 26 for receiving pins 28 which cause the rolls to rotate in the same direction and at the same angular velocity. Each of the rolls 4 has a raised flange or enlarged diameter portion 30 at its outer end and a shoulder 32 between the flange 3i) and the outer surface of the roll adjacent thereto. Each of the rolls increases in diameter from the shoulder 32 to its inner end with the diameter of the inner end of the roll being greater than the diameter of the flange 30. The belt B may be either a metal belt having a high modulus or a flexible belt, such as leather, having a low modulus. When using metal 2, belts araised, ring34 is provided on the inner end of each of the rolls, as shown in Figure 3. In the case of belts of lowmodulus a hollowness is provided in the rolls at the line of minimum distance between the base of the shoulders 32. Any suitable means may be provided for driving one of the-rolls 2.

The operation of the device is as follows: The end flanges 'provide a slightly raised shoulder 32 which remains tilted under rotation of the rolls 4, thus providing a funnel effect for the approaching belt B as clearly shown inFigure 1. Due to this funnelling effect the belt edges cannot contact the tilted fiangesuntil after the belt becomes seated on the roll body on the approach side and cannot contact the flanges after the belt B leaves the roll body on the delivery side. Ordinarily the rolls will center the belt B on the'ceuterpass line in the manner described in my Patent No. 2,593,157. If the belt B is forcedoff center between. the pulleys 2 by external forces such as lateral pressure applied'to either edge of the top or bottom strand the shoulders 32 will exert a slight pressure in the opposite direction to combat these external forces, thus maintaining the belt on the pass line over the pulleys. In the case of belts having low modulus characteristics the transverse hollowness referred to above, which amounts to several thousandths of an inch at-the line of minimum distance between flanges, will increase the pressure of the belt edges against the roll thus increasing thecentering efiect of theroll to retain the belt between the flanges. If the belt should move onto one ofthe flanges 30-it willbe recentered when the outside pressure is removed because the diameters of the inner ends of the rolls 4 are greater than the diameters of the raised flanges 30. When belts'of high modulus are used the rings 34 are added to greatly diminish or entirely eliminate the hollowness referred to above, this being necessaryto. prevent excessive bending of the strip or belt.

Figure 4 discloses a roll or pulley of the general type shown in Figure 10 of my above mentioned Patent No. 2,593,158. In this embodiment a straight shaft 36 is mounted in bearings 38. A pair of frusto conical rolls 40 are mounted on the shaft 36. The smaller or outer end of each of the rolls 40 is mounted on a bearing 42 and is provided with an opening 44 in which is received a collar 46 keyed or otherwise fastened to the shaft 36 for rotation therewith. Pins 48 extend from the collars 46 into openings 50 in the rolls 40. The collar 46 is held against the bottom of the opening 44 by means of a nut 52 threaded on the shaft 36. If desired, lock washers 53 may be provided for the nuts 52. The large end of each of the rolls 40 is provided with a bearing collar 54 having an inner diameter substantially greater than the outer diameter of the shaft 36 to permit deflection of the rims of the rolls inwardly at the point of pressure applied by the strip. Each of the rolls 40 is provided with a flange 56 similar to the flange 30. The belt supporting surface as shown consists of a covering 58, made of flexible material such as rubber, having a plurality of peripheral grooves 60 therein which extend inwardly toward the axis of rotation and away from the opposite roll. The flanges 56 prevent the rubber covering 58 from moving outwardly. This construction of the outer surface increases the centering effect in the manner described in my Patent No. 2,592,581. The pulley is otherwise the same as the pulley shown in Figure 2. In other words each roll increases in diameter from the flange 56 toward its inner end and the diameter of the inner end is greater than the diameter of the raised flange 56. The rubber covering 58 may be omitted and the rim constructed in the same manner as in the roll of Figure 2. The outer covering 58 may also be used with the roll of Figure 2. The outer covering 58 may be provided with a raised ring 34' as shown in Figure 7 whenusing belts or strip of high modulus. This ring 34' corresponds to the ring 34 .of Figure 3. It will be noted that the rim of the roll of Figure 4 will assume the same position under load as the rim of the roll of Figure 2. That is, the axes of rotation of the rolls under load will intersect at a point between the rolls and diverge away from the direction of approach of the object.

Figure 5 shows a form of apparatus in which the rolls of my invention may be used. A belt B" passes around a pair of pulleys 2 of my invention and also around a pressure former 70. A similar arrangement is provided in spaced relationship with this first arrangement. A

,mass of loose granular material M, such as wood shavings,

former 68. It has been found that if the rolls 63, 64, 65

and 67 are of the type disclosed above the belt B will track very satisfactorily over the rolls. It has also been found that the device will operate better if angle A is made small.

While several embodiments of my invention have been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the followingclaims.

I claim:

1. Apparatus for automatically centering a moving elongated object comprising a pair of opposed rotatable rolls over which the object passes, the axes of rotation of said rolls under load intersecting at a point between the rolls and diverging away from the direction of approach of the object, an enlarged diameter portion on each of said rolls at its outer end, a shoulder between each of said enlarged diameter portions and the surface of the roll adjacent thereto, the distance between said shoulders being sufiicient to receive the object therebetween, each of said rolls increasing in diameter from said shoulder toward its inner end, the diameter of the inner ends of said rolls being greater than the diameter of said enlarged diameter portions, and means for positively causing said rolls to rotate in the same direction and at the same angular velocity.

2. Apparatus for automatically centering a moving object according to claim 1 in which there is a hollowness in the rolls at the line of minimum distance between the bottom of said shoulders.

3. Apparatus for automatically centering a moving object according to claim 1 including a raised ring on the inner end of each of said rolls.

4. Apparatus for automatically centering a moving object according to claim 1 in which the object supporting surface of each of said rolls includes a flexible covering having a plurality of peripheral grooves therein extending inwardly toward the axis of rotation and away from the opposite roll.

5. Apparatus for automatically centering a moving object according to claim 4 in which there is a hollowness in the rolls at the line of minimum distance between the bottom of said shoulders.

6. Apparatus for automatically centering a moving object according to claim 4 including a raised ring on the inner end of each of said rolls.

References Cited in the file of this patent UNITED STATES PATENTS 677,333 Bartholomew- July 2, 1901 2,592,581 Lorig Apr. 15, 1952 2,593,157 Lorig Apr. 15, 1952 2,593,158 Lorig Apr. 15, 1952 FOREIGN PATENTS 616,947 Great Britain Jan. 28, 1949 

